The invention is concerned with setting the operating point of transistors, in particular bipolar transistors, in an integrated circuit in which the collector currents of the transistors are predetermined by the base-emitter currents. These base-emitter currents can be fixed by resistors, for example, via which the base-emitter paths are fed by a supply voltage. Setting of the operating point in this way has the advantage that relatively low operating voltages are possible with a minimum of operating current. The low operating voltage possible is a result of the fact that the emitter potentials, e.g. of npn transistors, can be directly connected to the negative terminal of the supply voltage. The minimum operating current is possible because only the base-emitter currents are required in addition to the collector currents needed for the circuit to function. The drawbacks of setting the operating point in this way are that with predetermined resistances for operating point setting, the collector currents depend on the current amplification factors of the transistors and on the base-emitter voltages that are obtained.
In general, negative-feedback arrays are used for operating point setting of transistors, such as negative emitter feedback, where an emitter-current-stabilizing resistor is provided and where the base is supplied with a fixed potential.